1. Field of the Invention
This invention relates to the field of ignition systems for internal combustion engines, and in particular to an improved electronic ignition system that supplements an existing ignition system, resulting in a higher quality spark ignition for more complete combustion of the fuel/air mixture in each cylinder of the engine during the compression stroke of the engine.
2. Brief Description of the Prior Art
Manufacturers of ignition systems for internal combustion engines have made many improvements over the basic breaker point type ignition systems which have been in use for decades. Many manufactures have replaced the breaker points and condenser arrangement with other types of mechanisms which detect the angular position of camshaft of the engine, and employ electronic devices to create the spark signal at the distributor for transmission to the spark plugs. However, such systems are generally replacement systems that are not supplemental to the original or existing ignition system of an internal combustion engine.
One such electronic ignition system is disclosed in U.S. Pat. No. 5,197,448 to Porreca et al. which shows and describes first and second energy sources which combine to initiate and sustain, respectively, an arc across a spark gap. The first energy source functions in a manner similar to a normal spark ignition system, and the second energy source is connected in series with the secondary winding of a step-up transformer and is only sufficient to sustain an arc, not to generate one. The electrical connections involving the generation of the second energy source is such that coupling with the primary winding is minimized.
In U.S. Pat. No. 5,638,799 to Kiess et al., a method is disclosed which employs steps of discharging a capacitor through a primary ignition coil to generate a first arc potential in a secondary ignition coil, and then induces a flyback signal from the primary to the secondary a predetermined time later. The first arc potential applied to the spark plugs is a negative going pulse, and the delayed second arc potential is an opposite polarity positive going pulse. The generation of a bipolar high voltage spark potential with negative and positive going pulses spaced apart by a predetermined time period is made possible by the use of a step-up transformer and the employment of a necessary isolation diode between the power supply (battery) and the circuitry.
Neither the Porreca et al. system nor the Kiess et al. system provides a second strike spark signal which may be combined with the spark signal generated by an existing induction ignition system to produce a composite spark signal output from the ignition coil to be distributed to the spark plugs. Moreover, neither prior art system produces a double strike pulse with both first and second spark signals of the same polarity and both generating arc potentials sufficient to ignite the fuel/air mixture in the engine cylinders.
In U.S. Pat. No. 6,123,063 there is described an ignition system which provides an augmenting spark signal overriding the spark signal provided by the basic ignition system of the engine and generating a plurality of such augmented spark signals for each original spark system.
The second strike ignition system of the present invention is, in a preferred embodiment of the present invention, a supplementary ignition system for existing induction coil ignition systems as used in internal combustion engines. It supplements the principal or first spark signal provided by the primary ignition system for the internal combustion engine. It does not alter or affect the existing first spark signal pulse. Supplementing the first spark signal with the second strike spark signal in a predetermined time sequence results in a longer duration of spark from the spark plug for each cycle of the engine and higher quality double strike spark during the compression stroke of the engine. The increased spark energy improves performance, improves gas mileage, increases horse power, reduces misfires, and decreases harmful or polluting emissions.
In other embodiments of the present invention, a second strike ignition system according to the principles of the present invention may be incorporated into the main ignition system of the engine to provide an automatic operation of the second strike therein.
In the above mentioned proffered embodiment wherein the invention herein is incorporated in an supplementary ignition system on an internal combustion engine, the main modular unit for the second strike ignition system is made small enough to be easily mounted close to the existing ignition system. Removal of mounting screws or nuts at the coil and the attachment of two wires to the exposed terminals of the coil, and another for a ground connection, complete the installation procedure. The main module is approximately 4.0xe2x80x3xc3x976.0xe2x80x3xc3x973.0xe2x80x3 and may be fastened to either the distributor housing or the ignition coil, or at other desired locations.
Manufactured as a supplemental ignition system, the second strike ignition system can be removed at any time with immediate reversal of the engine to the original equipment and its performance.
The second strike ignition system is preferably modular and includes a control board, a DC to DC converter, a housing, and a group of selection switches. The DC to DC converter and the control board lie within the housing. The selection switches may be mounted on the housing or, optionally, external thereto. The DC to DC converter is mounted directly to a base plate of the housing, and holes in one end plate of the housing provide access to external switches. Input power, ground, a tachometer drive signal, a control line to an on/off switch, and the connection to the negative terminal of the primary ignition signal enter through grommets at the other end plate. The base plate also serves as a grounding and heat dispersion surface.
The second strike ignition system interfaces with the engine via three wires which connect with the negative side of the ignition coil, positive battery voltage, and battery return (chassis ground).
The second strike ignition system electronics senses activation of the primary ignition spark. At the optimum time following the sensing of the primary induction spark, dependent on the engine""s characteristics, the second strike ignition system produces a supplementary induction spark signal in the primary of the ignition coil. The polarity of the two spark signals are the same and are integrated to produce two successive spark signals which cause the generation of two separate sparks at the spark plug at each cylinder during each cycle thereof which thus increases the spark energy delivered to the spark plug during each compression stroke.
When the second strike ignition system is configured as a supplemental ignition system, it monitors the first spark from the primary ignition system and provides a source of energy for a second spark that follows the primary ignition spark a predetermined time after the start of the first spark signal. The second strike ignition system works with all internal combustion engines having an induction ignition system, a distributor, and a single coil. As will be shown in the accompanying drawings and detailed description herein, the invention operates on a basic principle that impinging a delayed rising current in the opposite direction as the current created by the primary induction system results in output voltages and currents of the same polarity, the polarity that is favorable to the combustion process.
While the invention operates on the assumption that the primary ignition system sends a measurable signal to the second strike ignition system with the correct timing, the second strike ignition system reads the prime spark signal even if there is not sufficient energy to initiate the combustion of the fuel/air mixture in the cylinder. By sensing a low-level primary spark signal, the second strike ignition system will initiate the combustion of the fuel/air mixture with the second strike spark signal.